The importance of Higgs-boson pair production as a process allowing us to shed
more light on the Higgs potential is undisputed. Deviations from the Standard
Model (SM) form, manifesting themselves in anomalous Higgs-boson self-couplings,
would be a clear sign of new physics. If the Higgs-boson
trilinear coupling was found to be different from the SM value, small deviations in other Higgs couplings could also be expected. In order to expose such slight deviations, it is crucial to control the uncertainties of the theory
predictions, including the description of anomalous couplings within an
effective field theory (EFT) framework.
The theory uncertainties have various sources, the dominant ones in the SM
currently being uncertainties related to the treatment of the top-quark mass in
different renormalisation schemes.
NLO QCD corrections including the full top-quark mass dependence are
available [1]}, [2]}, [3]}, [4]}
and have been included in calculations where higher orders have been performed
in the heavy-top limit [5]}, [6]}, [7]}, thus
reducing the scale uncertainties and the uncertainties due to missing top-quark
mass effects, while the top-mass scheme uncertainties remain an
issue [8]}.
